A Microsoft-sponsored open-source project is expected on Friday to release a translator that will convert file formats between Microsoft Office and rival standard OpenDocument, or ODF. Microsoft started the project at SourceForge last year, relying on three partners to develop the code that lets a user open and save word processor documents in two different formats.

If you have a Windows platform, and you do not have a copy of MS Office, and you want to work with ODF format documents, you can use any of these: http://opendocumentfellowship.org/applicationsOffice suites
Application Native Status Platform
OpenOffice.org Yes 4 stars Linux, Windows, Mac
StarOffice Yes 4 stars Linux, Windows
Workplace Yes 3 stars Linux, Windows

Of those choices, OpenOffice is free to use, but it is a very large download. 94 MB for the file OOo_2.1.0_Win32Intel_install_en-US.exe .

OpenOffice.org has a batch translator feature. It will allow you to select a whole batch of MS Office documents and convert them all to ODF.

In the near future, the daVinci plugin, a version of MS Office and a "batch convert macro" may be able to do a better job of this task that the current OpenOffice does.